1. Field of the Invention
The present invention relates to a two-axis hinge device with rotation regulating function used in a folded and rotational mechanism of a small-sized electronic device such as a portable telephone, a notebook-sized personal computer, an electronic notebook, a DVD monitor or a remote controller, and configured to be rotatable about intersecting two axes in predetermined ranges, respectively.
2. Description of the Related Art
Generally, a two-folded portable telephone is configured so that a two-axis hinge device including a folding axis and a rotational axis connects a first case where a keyboard is disposed to a second case into which a liquid crystal display monitor (LCD) displaying an image is incorporated, thereby performing an operation for rotating the second case with the liquid crystal display monitor around the folding axis to open or close the second case with the keyboard relative to the first case and an operation for rotating the second case with the liquid crystal display monitor around the rotational axis to turn the second case with the liquid crystal display monitor the other way while the second case with the liquid crystal display monitor is open at, for example, 90 degrees.
The conventional two-axis hinge device used as stated above includes a rotation regulating mechanism that regulates a rotational operation of the solid (through-hole-free) rotation axis according to an opening or closing angle of the solid folding axis is disposed, thereby making it possible to restrict a rotatable region of the rotational axis according to a rotational (inclination) angle of the folding axis. Further, the rotation regulating mechanism enables an operation for viewing a monitor at a certain optimum position (e.g., a position at which the monitor is open at 90 degree) while rotating the monitor by arranging a liquid crystal display screen for the monitor on a blanket of the rotational axis in, for example, a portable terminal device and arranging a key operating panel on a blanket of the folding axis. Furthermore, there is proposed a rotation regulating mechanism provided in the portable terminal device and preventing a failure from occurring if the key operating panel collides against the monitor by rotation of the monitor (see, for example, Patent Document 1).
There is also conventionally proposed a two-axis hinge device configured so that an air core pipe axis is used as the rotational axis and a harness (a fine electric wire) passes through a hollow of the rotational axis, thereby facilitating wiring, improving functions, and making the device small in size and light in weight (see, for example, Patent Document 2).
If the rotational axis is formed into a hollow pipe shape so as to facilitate wiring by passing the harness through the hollow of the rotational axis, such a conventional two-axis hinge device is made large in size so that the rotation regulating mechanism may sufficiently regulate operation. Accordingly, it is difficult to reduce the size of the two-axis hinge device by forming the rotation regulating mechanism integrally with the hollow rotational axis. Moreover, the two-axis hinge device has the following problem that a harness that passes through the hollow of the rotational axis including the rotation regulating mechanism is sandwiched between constituent members of the rotation regulating mechanism and is broken.    Patent Document 1: Japanese Patent Application Laid-Open (JP-A) No. 2004-360758    Patent Document 2: JP-A No. 2005-172133